Volumetric remodeling of the proximal left coronary artery: Early versus late after heart transplantation

OBJECTIVES The aim of this study was to characterize progression of cardiac allograft vasculopathy (CAV) with special respect to coronary artery geometry. BACKGROUND As previously shown by intravascular ultrasound (IVUS), CAV is characterized by a multifocal intimal hyperplasia. Little is known, however, about vascular remodeling processes influencing vessel geometry and luminal narrowing. METHOD In 30 heart transplant recipients serial IVUS studies were performed at baseline (BL) and after a mean follow-up period of 12.5 +/- 2.5 months. Changes in plaque, lumen and vessel volume were assessed in the proximal left anterior descending artery. Pattern of remodeling was analyzed in patients "early" (n = 15, BL study 1.4 +/- 0.7 months after heart transplantation [HTX]) compared with "late" after HTX (n = 15, BL 46.1 +/- 29.1 months). RESULTS Plaque volume was found to increase by a mean of 23.8 +/- 25.9 mm(3), not significantly different within and beyond the Ist year after HTX. Significant differences, however, were observed in changes in vessel volume with a mean decrease of -52.8 +/- 70.9 mm(3) in the early group, whereas late follow-up group presented with an enlargement of 32.3 +/- 45.0 mm(3). Based on these changes, lumen volume decreased by -73.2 +/- 69.8 mm(3) early, in contrast to a slight increase of 5.2 +/- 32.6 mm(3) in the late group. CONCLUSIONS Progression of CAV is a complex process, modified by changes in the vascular geometry. Especially within the Ist year after HTX, luminal loss is influenced not only by an increase in plaque area but by a decrease in total vessel volume as well. (C) 1999 by the American College of Cardiology.